A printed circuit board, abbreviated as PCB, is not only a critical electronic component, but also a support for electronic components, as well as an electrical connection carrier of the electronic components. It is referred as to the “printed” circuit board as being manufactured by an electron printing process.
A typical PCB includes a wiring layer partitioned into a digital region and an analog region, which is obtained by partitioning a copper surface on the wiring layer of the PCB at a joint edge between the digital region and the analog region, so that a certain insulation gap is formed between copper in two regions. Then a plurality of magnetic beads is arranged to connect the digital region with the analog region, so as to provide a return loop for an analog signal.
Since the wiring layer of the typical PCB is partitioned in such manner, it is difficult to control partition spacing. Further, copper coils of large area in the digital region and the analog region are insulated and separated from each other only through a short distance, and thus a large amount of electromagnetic interference will be generated therebetween. Furthermore, at a PCB layout stage, it is likely to neglect a component or a wire across the partition, resulting in a weak control.